Display backlight normalization

Abstract

Techniques for displaying images of different dynamic ranges in a display system are provided. In some embodiments, images that have a number of dynamic ranges may be normalized to a configured dynamic range that corresponds to the full intensity reproduction capability of the device. The configured dynamic range may be wider, greater, or deeper than the relatively limited dynamic range.

What is claimed is: 
     
       1. A method for rendering images on a high dynamic range display system comprising:
 receiving a first image; 
 determining, based on the first image, a first dynamic range of luminous intensity; 
 normalizing the first dynamic range of luminous intensity to a first configured dynamic range of luminous intensity; 
 rendering the first image on the display system using the configured dynamic range of luminous intensity; 
 outputting first image on the display system; 
 receiving a second image, wherein the second image is different from the first image; 
 determining, based on a second different image, a second dynamic range of luminous intensity, the second dynamic range being determined from the second image and differing from the first dynamic range; 
 wherein the first dynamic range represents a wider dynamic range than the second dynamic range; 
 normalizing the second dynamic range of luminous intensity to the second configured dynamic range of luminous intensity the first configured dynamic range is less than the second configured dynamic range; and 
 rendering the second image on the display system using the second configured dynamic range of luminous intensity; 
 outputting second image on the display system; 
 wherein at least one of the first image and the second image comprises a low dynamic range (LDR) image, one of the first and second configured dynamic range comprises a high dynamic range (HDR), and at least one of the first dynamic range and the second dynamic range is smaller than one of the first and second configured dynamic range; 
 wherein the steps of rendering the images comprises rendering the images on a locally dimmed display and normalizing the backlights of the display to a range of values having an upper limit that is less than the maximum light output level to which a backlight can be set but which comprises a light output level to produce an upper limit of a dynamic range selected for display of the images; and 
 wherein the display system further comprises a dynamic range control to a user; the dynamic range control configured to accept a selection by the user of a configured dynamic range from at least two configurable dynamic ranges as supported by the display system. 
 
     
     
       2. The method of  claim 1 , wherein one of the first and second configured dynamic range corresponds to the full luminous intensity reproduction capability of the display system. 
     
     
       3. The method of  claim 1 , wherein the second image comprises an image to be rendered by the display system next in time to the first image. 
     
     
       4. The method of  claim 1 , wherein the normalization of the second dynamic range is independent of an influence by the normalization of the first image. 
     
     
       5. The method of  claim 1 , wherein at least one of the first image and the second image comprises a high dynamic range (HDR) image. 
     
     
       6. The method of  claim 1 , wherein one of the first and second configured dynamic range is produced at least in part by a plurality of light sources, and wherein each individual light source in the plurality of light sources is individually settable to an individual light output level. 
     
     
       7. The method of  claim 1 , wherein normalizing the first dynamic range of luminous intensity to a configured dynamic range of luminous intensity includes mapping a first upper limit of the first dynamic range to an upper limit of the configured dynamic range. 
     
     
       8. The method of  claim 7 , wherein mapping the first upper limit to an upper limit of the configured dynamic range is performed based on a normalization function. 
     
     
       9. The method of  claim 8 , wherein the normalization function comprises a linear function. 
     
     
       10. The method of  claim 8 , wherein the normalization function comprises a non-linear function. 
     
     
       11. The method of  claim 1 , wherein at least one of the first image and the second image comprises a still image. 
     
     
       12. A method for rendering images on a high dynamic range display system comprising:
 receiving a pair of images, wherein the second image of the image pair is different from the first image of the image pair; 
 normalizing dynamic ranges of a pair of images respectively to a first and a second configured dynamic range respectively, wherein a first image of the image pair has a first dynamic range and the second image of the image pair has a second dynamic range, and wherein the first configured dynamic range and the second configured dynamic range configured to be selectable by a user and wherein the first configured dynamic range is less than the second configured dynamic range; 
 wherein the first dynamic range is wider, greater, or deeper than the second dynamic range; and 
 rendering each image of the image pair with the first and the second configured dynamic range respectively; 
 outputting the first image and the second images on the display system; 
 wherein the step of rendering each image comprises rendering the images on a locally dimmed display and normalizing the backlights of the display to a range of values having an upper limit that is less than the maximum light output level to which a backlight can be set but which comprises a light output level sufficient to produce an upper limit of a dynamic range selected for display of the images; and 
 wherein the display system further comprises a dynamic range control to a user; the dynamic range control configured to accept a selection by the user of a configured dynamic range from at least two configurable dynamic ranges as supported by the display system. 
 
     
     
       13. A display system configured to perform the method recited in  claim 1 . 
     
     
       14. An apparatus comprising a processor and configured to perform the method recited in  claim 12 . 
     
     
       15. A non-transitory computer readable storage medium, comprising software instructions, which when executed by one or more processors cause performance of the method recited in  claim 1 .